| /* Motorola m68k target-dependent support for GNU/Linux. |
| |
| Copyright 1996, 1998, 2000, 2001, 2002, 2003 Free Software Foundation, |
| Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "defs.h" |
| #include "gdbcore.h" |
| #include "frame.h" |
| #include "target.h" |
| #include "gdb_string.h" |
| #include "gdbtypes.h" |
| #include "osabi.h" |
| #include "regcache.h" |
| #include "objfiles.h" |
| #include "symtab.h" |
| #include "m68k-tdep.h" |
| |
| /* Offsets (in target ints) into jmp_buf. */ |
| |
| #define M68K_LINUX_JB_ELEMENT_SIZE 4 |
| #define M68K_LINUX_JB_PC 7 |
| |
| /* Check whether insn1 and insn2 are parts of a signal trampoline. */ |
| |
| #define IS_SIGTRAMP(insn1, insn2) \ |
| (/* addaw #20,sp; moveq #119,d0; trap #0 */ \ |
| (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \ |
| /* moveq #119,d0; trap #0 */ \ |
| || insn1 == 0x70774e40) |
| |
| #define IS_RT_SIGTRAMP(insn1, insn2) \ |
| (/* movel #173,d0; trap #0 */ \ |
| (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \ |
| /* moveq #82,d0; notb d0; trap #0 */ \ |
| || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40)) |
| |
| /* Return non-zero if PC points into the signal trampoline. For the sake |
| of m68k_linux_frame_saved_pc we also distinguish between non-RT and RT |
| signal trampolines. */ |
| |
| static int |
| m68k_linux_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| { |
| CORE_ADDR sp; |
| char buf[12]; |
| unsigned long insn0, insn1, insn2; |
| |
| if (read_memory_nobpt (pc - 4, buf, sizeof (buf))) |
| return 0; |
| insn1 = extract_unsigned_integer (buf + 4, 4); |
| insn2 = extract_unsigned_integer (buf + 8, 4); |
| if (IS_SIGTRAMP (insn1, insn2)) |
| return 1; |
| if (IS_RT_SIGTRAMP (insn1, insn2)) |
| return 2; |
| |
| insn0 = extract_unsigned_integer (buf, 4); |
| if (IS_SIGTRAMP (insn0, insn1)) |
| return 1; |
| if (IS_RT_SIGTRAMP (insn0, insn1)) |
| return 2; |
| |
| insn0 = ((insn0 << 16) & 0xffffffff) | (insn1 >> 16); |
| insn1 = ((insn1 << 16) & 0xffffffff) | (insn2 >> 16); |
| if (IS_SIGTRAMP (insn0, insn1)) |
| return 1; |
| if (IS_RT_SIGTRAMP (insn0, insn1)) |
| return 2; |
| |
| return 0; |
| } |
| |
| /* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */ |
| #define SIGCONTEXT_PC_OFFSET 26 |
| |
| /* Offset to saved PC in ucontext, from <asm/ucontext.h>. */ |
| #define UCONTEXT_PC_OFFSET 88 |
| |
| /* Get saved user PC for sigtramp from sigcontext or ucontext. */ |
| |
| static CORE_ADDR |
| m68k_linux_sigtramp_saved_pc (struct frame_info *frame) |
| { |
| CORE_ADDR sigcontext_addr; |
| char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; |
| int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT; |
| int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT; |
| |
| /* Get sigcontext address, it is the third parameter on the stack. */ |
| if (get_next_frame (frame)) |
| sigcontext_addr |
| = read_memory_unsigned_integer (get_frame_base (get_next_frame (frame)) |
| + FRAME_ARGS_SKIP |
| + sigcontext_offs, |
| ptrbytes); |
| else |
| sigcontext_addr |
| = read_memory_unsigned_integer (read_register (SP_REGNUM) |
| + sigcontext_offs, |
| ptrbytes); |
| |
| /* Don't cause a memory_error when accessing sigcontext in case the |
| stack layout has changed or the stack is corrupt. */ |
| if (m68k_linux_pc_in_sigtramp (get_frame_pc (frame), 0) == 2) |
| target_read_memory (sigcontext_addr + UCONTEXT_PC_OFFSET, buf, ptrbytes); |
| else |
| target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes); |
| return extract_unsigned_integer (buf, ptrbytes); |
| } |
| |
| /* Return the saved program counter for FRAME. */ |
| |
| static CORE_ADDR |
| m68k_linux_frame_saved_pc (struct frame_info *frame) |
| { |
| if (get_frame_type (frame) == SIGTRAMP_FRAME) |
| return m68k_linux_sigtramp_saved_pc (frame); |
| |
| return read_memory_unsigned_integer (get_frame_base (frame) + 4, 4); |
| } |
| |
| /* The following definitions are appropriate when using the ELF |
| format, where floating point values are returned in fp0, pointer |
| values in a0 and other values in d0. */ |
| |
| /* Extract from an array REGBUF containing the (raw) register state a |
| function return value of type TYPE, and copy that, in virtual |
| format, into VALBUF. */ |
| |
| static void |
| m68k_linux_extract_return_value (struct type *type, char *regbuf, char *valbuf) |
| { |
| if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| { |
| DEPRECATED_REGISTER_CONVERT_TO_VIRTUAL (FP0_REGNUM, type, |
| regbuf + REGISTER_BYTE (FP0_REGNUM), |
| valbuf); |
| } |
| else if (TYPE_CODE (type) == TYPE_CODE_PTR) |
| memcpy (valbuf, regbuf + REGISTER_BYTE (M68K_A0_REGNUM), |
| TYPE_LENGTH (type)); |
| else |
| memcpy (valbuf, |
| regbuf + (TYPE_LENGTH (type) >= 4 ? 0 : 4 - TYPE_LENGTH (type)), |
| TYPE_LENGTH (type)); |
| } |
| |
| /* Write into appropriate registers a function return value of type |
| TYPE, given in virtual format. */ |
| |
| static void |
| m68k_linux_store_return_value (struct type *type, char *valbuf) |
| { |
| if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| { |
| char raw_buffer[REGISTER_RAW_SIZE (FP0_REGNUM)]; |
| DEPRECATED_REGISTER_CONVERT_TO_RAW (type, FP0_REGNUM, valbuf, raw_buffer); |
| deprecated_write_register_bytes (REGISTER_BYTE (FP0_REGNUM), |
| raw_buffer, TYPE_LENGTH (type)); |
| } |
| else |
| { |
| if (TYPE_CODE (type) == TYPE_CODE_PTR) |
| deprecated_write_register_bytes (REGISTER_BYTE (M68K_A0_REGNUM), |
| valbuf, TYPE_LENGTH (type)); |
| deprecated_write_register_bytes (0, valbuf, TYPE_LENGTH (type)); |
| } |
| } |
| |
| /* Extract from an array REGBUF containing the (raw) register state |
| the address in which a function should return its structure value, |
| as a CORE_ADDR. */ |
| |
| static CORE_ADDR |
| m68k_linux_extract_struct_value_address (char *regbuf) |
| { |
| return *(CORE_ADDR *) (regbuf + REGISTER_BYTE (M68K_A0_REGNUM)); |
| } |
| |
| static void |
| m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| |
| tdep->jb_pc = M68K_LINUX_JB_PC; |
| tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE; |
| |
| set_gdbarch_deprecated_frame_saved_pc (gdbarch, |
| m68k_linux_frame_saved_pc); |
| set_gdbarch_deprecated_extract_return_value (gdbarch, |
| m68k_linux_extract_return_value); |
| set_gdbarch_deprecated_store_return_value (gdbarch, |
| m68k_linux_store_return_value); |
| set_gdbarch_deprecated_extract_struct_value_address (gdbarch, |
| m68k_linux_extract_struct_value_address); |
| |
| set_gdbarch_pc_in_sigtramp (gdbarch, m68k_linux_pc_in_sigtramp); |
| |
| /* Shared library handling. */ |
| set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section); |
| set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| } |
| |
| void |
| _initialize_m68k_linux_tdep (void) |
| { |
| gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX, |
| m68k_linux_init_abi); |
| } |